1. Field of the Invention
This invention relates to a height-adjusting collapsible mechanism for a button key and more particularly to an adjustable scissor-type linkage that is able to change a key""s or a keyboard""s height of a notebook computer.
2. Description of the Prior Art
In conventional notebook computers, a button key in the keyboard is usually supported thereunder by a collapsible mechanism, a rubber dome and a touch control circuit. FIG. 1 shows a typical button key mounted on a substrate 10 of a notebook computer. The button key 1 has a key top 11 for receiving external force and a collapsible means 12 which has two pairs of symmetrical scissors-type levers to support the button key 1 and thus to enable the button key 1 capable of being lifted upward or depressed downward. As shown, a hollow rubber dome 13 is located under the button key 1 and arranged between the levers to provide restore pressure for resuming the height of the button key 1 after the depressed force upon the button key 1 being released. The touch control circuit (not shown in the figure) is located on the substrate 10 under the rubber dome 13. When the key top 11 and the rubber dome 13 are free from any external force, the button key 1 is defined at a xe2x80x9cfree heightxe2x80x9d state.
In the following description, only the button key 1 and collapsible means 12 will be shown in the figures and text. The rubber dome 13 and the touch control circuit function are well known in prior art and thus will be omitted. Similar components will be marked by similar numerals in the description below to ease reading, whether they are in the prior art or belong to this invention.
FIG. 2 shows a conventional collapsible means 12 for a button key 1, located between a bottom side 110 of the key top 11 and the substrate 10. the button key 1 has a first lever 121 crossly engaged with a second lever 122 at a pivotal point 123 to form a substantially X-shaped or scissors-type linkage. Two sets of such linkage are disposed at two opposing sides of the button key 1 under the key top 11. The first lever 121 has a first top end 1211 pivotally engaged with a first hub 1101 located under the bottom side 110 and a first bottom end 1212 pivotally and slidably engaged with a turn-slide hub 101 located on the substrate 10. The second lever 122 has a second top end 1221 pivotally and slidably engaged with a second L-shaped flange 1102 located below the bottom side 110 and a second bottom end 1222 pivotally engaged with a fourth hub 102 located on the substrate 10. The first and second levers 121 and 122 thus form the collapsible means 12 that may be moved up or down under external force.
As shown, the first top end 1211 and the second bottom end 1222 are substantially located on the same first fixed vertical line L. The second top end 1221 and first bottom end 1212 are substantially located on a second vertical line Lxe2x80x2 which may be moved slightly horizontally. When the key top 11 subjects to a downward or uplift pressure, the first top end 1211 and the second bottom end 1222 are pivotally turnable respectively in the first and fourth hub 1101 and 102, while the second top end 1221 and the first bottom end 1212 are turnable and slidable respectively on the second flange 1102 and turn-slide hub 101 and may move the second vertical lines Lxe2x80x2 sideward or horizontally.
Although this mechanism may allow the button key to be lifted or lowered steadily, yet it has a fixed free height for the button key or the whole keyboard. Such a fixed free height restriction to the conventional button key structure does causes some design and usage problems. For instance, when using computers on a desktop, users mostly accustom or prefer to the standard keyboards that have button keys of greater free height. There are also some keyboard designs that would have greater free height for some special function keys (such as Tab key) than other button keys. However, in notebook computers that are highly focused to slim size and lightweight, a fixed free height button key or keyboard becomes a serious design issue.
In order to make the notebook computer more compact, the free height of button keys is used to be designed as small as possible for saving the thickness thereof, but from which the using of the keyboard would become awkward and inconvenient. To make the operation of the notebook computer more comfortable, the free height of the button key should be increased to a level for most users able to get along easily. However, to increase the free height of the button keys would definitely make the notebook computer bulky. Therefore, how to get a better design upon the aforesaid issues is still a problem begging for improvement.
It is an object of this invention to provide a height-adjusting collapsible mechanism for a button key that may make the free height for a button key or the keyboard adjustable to suit various requirements of users.
It is another objet of this invention to provide a height-adjusting collapsible mechanism that enables a notebook computer to have a greater keyboard height when in use and a smaller keyboard height when packed for storing and carrying, so that the computer may be made to a small size without sacrificing its normal function and convenience.
The height-adjusting collapsible mechanism of this invention includes a key top, a substrate and a pair of collapsible means to support the key top for up and down movement above the substrate. Each collapsible means has a first lever pivotally crossed with a second lever. Each of the first and the second levers has respectively one pivotal end for forming a first vertical connecting line above the substrate, and has respectively another pivotal end for forming a second vertical connecting line above the substrate and spaced from the first vertical connecting line in a first direction at a distance of a first interval. The bottom end of the first lever is engageable with a hub located on the substrate. The space between the first and the second vertical lines is defined as an inner side and the space beyond the second vertical line is defined as an outer side. In general, this invention includes at least one movable stopper engageable with the hub so that the first interval may be changed to result in change of the free height of the button key when the stopper is moved sideward or horizontally against the substrate.
In one aspect of the present invention, the stopper may be located in a slide groove formed in the substrate for the stopper to move sideward smoothly. The inner side may have a bordering edge for limiting the movement of the bottom end of the first lever.
In another aspect of the present invention, the stopper may have an adjusting end located at the outer side to facilitate movement of the stopper for changing the first interval and consequently changing the free height of the button key. The adjusting end may be a rigid or resilient member separately made or be integrally formed with the stopper. The resilient member may be a spring, an elastic metal strip and the like.
In a further aspect of the present invention, the substrate may have a slide groove formed therein in the first direction. The stopper is movable in the slide groove for moving the hub. The stopper may also be located on the hub which becomes movable.
In yet another aspect of the present invention, it may be applied to one or more keys in a keyboard. It may also be used for the whole keyboard. In this case, multiple number of this invention will be laid on the substrate at a selected pattern. The stoppers will be connected together and be actuated by a height-adjusting means for changing the free height of the keyboard as desired. The collapsible mechanism will have a control point to work with the height-adjusting means. The height-adjusting means may be located between the substrate and keys and may have a bordering side. The height-adjusting means may be moved to one position to make the bordering edge making contact with the control point at the free height state. Moving the height-adjusting means to another position will make the bordering side moving away from the control point, then the crossing angle between the first and the second levers will be changed for thus altering the free height of the keyboard.
In yet another aspect of the present invention, the substrate may include at least one slide rail for the height-adjusting means to slide thereon. The sliding relationship between the substrate and height-adjusting means may be a form of rail-groove or groove-rail coupling manner. The control point may be at a selected location on the lever, but is preferably at one end of the lever. The height-adjusting means may also has openings formed therein to enable the scissors mechanism passing therethrough for mounting onto the substrate. The bordering side may also be located in the openings, i.e. in the inner side.
In still another aspect of the present invention, this invention may include an actuating means to receive an external force or manual force for moving the height-adjusting means. The actuating means may include a driver end attached to the display screen of the notebook computer and a driven end attached to the height-adjusting means located in the computer body. When the notebook computer is closed with the display screen folded over the body, the driver end will move the driven end to lower the free height of the keyboard to a compact size for facilitating storage and portability. When the screen is opened and lifted, the actuating means will raise the free height of the keyboard to a higher level for adding user""s comfort in using the notebook computer. The actuating means may be a cam mechanism to achieve aforesaid purpose.